1. Field of the Invention
The present invention relates generally to accessories for power hand tool, and more particularly to a battery module for a power hand tool.
2. Description of the Related Art
The battery of a regular power hand tool needs to have a high electricity storage capacity to supply long life power to the power hand tool. Therefore, Li-ion battery is the main choice for power hand tools.
A Li-ion battery has a high electricity storage capacity, however it generates much heat energy during charging, thereby increasing the temperature. There are battery chargers that have heat dissipation means to dissipate heat when charging a battery. However, the heat dissipation means simply dissipates heat from the battery charger, having no significant effect in lowering the temperature of the battery, and the battery under charging may burn out due to excessively high temperature.